Abstract

This work presents a simplified model of microwavescattering during the avalancheionization stage of laser breakdown and corresponding experimental results of microwavescattering from laser breakdown in room air. The model assumes and measurements confirm that the breakdown regime can be viewed as a point dipole scatterer of the microwave radiation and thus directly related to the time evolving number of electrons. The delay between the laser pulse and the rise of the microwavescattering signal is a direct measure of the avalancheionization process.